Inter - one of Italy's biggest and most famous clubs - have built links with the Zapatistas by funding sports, water and health projects in their area of operation in Chiapas.

Team manager Bruno Bartolozzi paid a visit to a village in Chiapas last June, bearing donations from the club and its owner, Massimo Moratti. During the trip, he was approached by a Zapatista commander.

Zanetti, an Argentine, also wrote a letter to express his support for the rebels' "struggle to maintain your roots and fight for your ideals".

The club told the BBC News website that no decision had been made on whether to accept the challenge.

The Zapatistas are demanding greater autonomy and indigenous rights. Their campaign has been largely peaceful since January 1994, when at least 150 people died in clashes.